Question

In an atom, the first energy level can hold

_____ electrons. The second energy level can hold ____
electrons. The third energy level can hold _____
electrons.

Answer 1

2, 8, 18

Step-by-step explanation:

The number of orbitals for any level of interest n is calculated by a formula
`o = n^2`. Since each orbital contains a maximum of 2 electrons, we can calculate the total number of electrons in an nth orbital by
`e = 2n^2`.

• As a result, the first energy level for n = 1 can hold a maximum of
  `2n_1^2 = 2\cdot 1^2 = 2` electrons,
• The second energy level can hold a maximum of
  `2n_2^2 = 2\cdot 2^2 = 8` electrons,
• The third energy level can hold a maximum of
  `2n_3^2 = 2\cdot 3^2 = 18` electrons.